240 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Bill about as long as head to decidedly longer, nearly straight, 

 much compressed, its width at latero-frontal antise much less than 

 its depth at same point and contained from three and a half to nearly 

 six times in distance from nostril to tip of maxilla ; culmen distinctly 

 to obsoletely ridged, straight for basal half (more or less), gently 

 decurved terminally, the tip of maxilla rather strongly decurved but 

 scarcely uncinate; tomia more or less decurved terminally, without 

 trace of subterminal notch; gonys straight or (sometimes) very faintly 

 concave, sUghtly promment basally, sometimes very faintly decurved 

 at tip. Nostril exposed, posteriorly in contact with latero-frontal 

 feathering, roundish or broadly oval, nonoperculate. Rictal bristles 

 absent. Wing moderate, rather pointed, the longest primaries exceed- 

 ing secondaries by less than to decidedly more than length of tarsus; 

 seventh and eighth, sixth, seventh, and eighth, or sixth and seventh, 

 primaries longest, the tenth (outermost) about three-fourths as long 

 as the longest, the ninth longer than fourth, usually ( ?) longer than 

 fifth. Tail less than four-fifths to more than six-sevenths as long as 

 wing, graduated for about one-third its length, the rectrices (12) 

 conspicuoush^ acuminate, with the very strong and rigid shafts 

 decurved and somewhat twisted terminally. Tarsus shorter to 

 shghtly longer than bill from nostril, less than one-fourth as long as 

 wing, rather slender, distinctly scutellate (endaspidean) ; middle toe, 

 with claw, slightly longer than tarsus; outer toe (with or without 

 claw) as long as middle toe; inner toe (without claw) reaching to 

 subterminal articulation of middle toe, its claw falling short of base 

 of middle claw; hallux decidedly shorter than inner toe, scarcely 

 stouter; middle toe united for whole of first and part of second 

 phalanx to outer toe, for whole of first phalanx to inner toe; claws 

 large, those of anterior toes very strongly curved and acute, that of 

 hallux less strongly curved, less acute, as long as or longer than the 

 digit. 



Coloration.— liiim.\>, upper tail-coverts, tail, and remiges (at least 

 partly) plain cinnamon-rufous or chestnut; pileum, hindneck, and 

 back brown, olive, or black, usuall}?" streaked or spotted with buff; 

 under parts browm, bulfy grayisli, or ohve, striped or spotted wdth 

 buffy, sometimes squamated with black on a l)uffy ground; chin and 

 throat buff, sometimes immaculate, sometimes spotted or barred 

 with olive. Sexes alike. 



Range. — Southern Mexico to Cayenne, eastern and central Brazil, 

 Bolivia, and Peru. (About thirty species and subspecies.") 



KEY TO THE SPECIES AND SUBSPECIES OF XIPHORHYNCHUS. 



a. Under parts striped or streaked with buffy. 



b. Back black, with broad streaks of buff; under parts striped with black and buff. 

 {Xiphorhynchus lachrymosus.) 



o About half of them have not been examined in this connection. 



